import commonPasswords from '../data/commonPasswords';
import Trie from './Trie';

const checkStrength = (pass: string) => {
    const score = scorePassword(pass);
    const scoreLabel = mapScoreToLabel(score);
    const hints = getImprovementHints(pass);
    return {
        score,
        scoreLabel,
        hints,
    };
};

export default checkStrength;

// Function to score the password based on different criteria
const scorePassword = (password: string): number => {
    if (password.length <= 8 || isCommonPassword(password)) return 0;

    let score = 0;
    score += getLengthScore(password); //3
    score += getSpecialCharScore(password); //1
    score += getCaseMixScore(password); //1
    score += getNumberMixScore(password); //1

    return Math.min(score, 6); // Maximum score is 6
};

// Initialize the Trie with common passwords
const trie = new Trie();
commonPasswords.forEach((password) => trie.insert(password));
const isCommonPassword = (password: string): boolean => {
    // return commonPasswords.includes(password);
    return trie.search(password);
};

// Length-based scoring
const getLengthScore = (password: string): number => {
    if (password.length > 20 && !hasRepeatChars(password)) return 3;
    if (password.length > 12 && !hasRepeatChars(password)) return 2;
    if (password.length > 8) return 1;
    return 0;
};

// const hasRepeatChars = (password: string): boolean => {
//     const repeatCharRegex = /(\w)(\1+\1+\1+\1+)/g;
//     return repeatCharRegex.test(password);
// };
// Check for repeated characters
const hasRepeatChars = (password: string): boolean => /(\w)\1{3,}/.test(password);

// Function to get the score based on the presence of special characters
const getSpecialCharScore = (password: string): number => {
    const specialCharRegex = /[^A-Za-z0-9]/g;
    return specialCharRegex.test(password) ? 1 : 0;
};

// Function to get the score based on the mix of uppercase and lowercase letters
const getCaseMixScore = (password: string): number => {
    const hasUpperCase = /[A-Z]/.test(password);
    const hasLowerCase = /[a-z]/.test(password);
    return hasUpperCase && hasLowerCase ? 1 : 0;
};

// Function to get the score based on the mix of letters and numbers
const getNumberMixScore = (password: string): number => {
    const hasLetter = /[A-Za-z]/.test(password);
    const hasNumber = /[0-9]/.test(password);
    return hasLetter && hasNumber ? 1 : 0;
};

// Function to map the score to a corresponding label
const mapScoreToLabel = (score: number): string => {
    const labels = ['risky', 'guessable', 'weak', 'safe', 'secure', 'safe-secure', 'optimal'];
    return labels[score] || '';
};

// Function to get improvement hints
const getImprovementHints = (password: string): string[] => {
    const hints = [];

    if (password.length <= 8) {
        hints.push('Increase your password length to more than 8 characters for 1 scoring point.');
    } else {
        if (password.length > 8 && password.length <= 12) {
            hints.push('Increase your password length to more than 12 characters for additional scoring point.');
        } else if (password.length > 12 && password.length <= 20) {
            hints.push('Increase your password length to more than 20 characters for additional scoring point.');
        }

        // Check for special character score
        if (!getSpecialCharScore(password)) {
            hints.push('Include at least one special character for 1 point.');
        }

        // Check for case mix score
        if (!getCaseMixScore(password)) {
            hints.push('Mix uppercase and lowercase letters for 1 point.');
        }

        // Check for number mix score
        if (!getNumberMixScore(password)) {
            hints.push('Add numbers to your password for 1 point.');
        }

        if (hasRepeatChars(password) && password.length < 20) {
            hints.push('Remove repeated characters for 1 point.');
        }
        if (hasRepeatChars(password) && password.length > 20) {
            hints.push('Remove repeated characters for 2 points.');
        }
    }

    return hints;
};